Xavier Perret

Microbial Genetics

Research Interests

We study various aspects of nitrogen fixing symbioses between legumes and rhizobia, including the molecular mechanisms that control bacterial entry into plant tissues and the diversity of rhizobia in fields and forests. Molecular studies primarily focus on the roles in symbioses of nodulation factors, surface polysaccharides and type three effector proteins secreted by the promiscuous strain Sinorhizobium fredii NGR234. Our longterm objective is to synthesize de novo a minimal symbiotic plasmid that confers broad host-range nodulation to recipient soil bacteria. By contrast, field studies aim at identifying the most proficient symbionts that foster growth of selected plant species. Targeted legumes include pigeon pea in Côte d'Ivoire, chickpea and fenugreek in Tunisia and Lotus corniculatus in Switzerland.